Computation of ship hydrodynamic interaction forces in restricted waters using potential theory

Abstract

A computer code based on the double-body potential flow model and the classic source panel method has been developed to study various problems of hydrodynamic interaction between ships and other objects with solid boundaries including the seabed. A peculiarity of the proposed implementation is the application of the so-called “moving-patch” method for simulating steady boundaries of large extensions. The method is based on an assumption that at any moment just the part of the boundary (“moving patch”) which lies close to the interacting ship is significant for the near-field interaction. For a specific case of the flat bottom, comparative computations were performed to determine optimal dimensions of the patch and of the constituting panels based on the trade-off between acceptable accuracy and reasonable efficiency. The method was applied to estimate the sway force on a ship hull moving obliquely across a dredged channel. The method was validated for a case of ship-to-ship interaction when tank data were available. This study also contains a description of a newly developed spline approximation algorithm necessary for creating consistent discretizations of ship hulls with various degrees of refinement.

Keywords

ship hydrodynamic interaction / restricted waters / moving panelled patch method / potential theory

References

[1] Chen HC, Lin WM, Liut DA, Hwang WY (2003). An advanced viscous flow computation method for ship-ship dynamic interactions in shallow and restricted waterway. Proceedings of International Conference on Marine Simulation and Ship Maneuverability (MARSIM’03), Kanazawa, Japan, 3, RC-35-1-10.

[2] Ch’ng P.W., Doctors L.J., Renilson M.R. A method of calculating the ship-bank interaction forces and moments in restricted water. International Shipbuilding Progress, 1993, 40(421): 7-23

[3] Ch’ng P.W. An investigation into the influence of bank effect on ship manoeuvring and its mathematics modeling for a ship-handling simulator, 1991, Sydney: School of Mechanical and Manufacturing Engineering, The University of New South Wales

[4] Fonfach J.M., Sutulo S., Guedes Soares C. Numerical study of ship-to-ship interaction forces on the basis of various flow models. Proceedings of the 2nd International Conference on Ship Manoeuvring in Shallow and Confined Water STS, 2011, Norway: Trondheim, 137-146

[5] Hess J.L., Smith A.M.O. Calculation of nonlifting potential flow about arbitrary three-dimensional bodies. Journal of Ship Research, 1964, 8(2): 22-44

[6] Hess J.L., Smith A.M.O. Calculation of potential flow about arbitrary bodies. Progress in Aeronautical Sciences, 1967, 8: 1-137

[7] Lataire E, Vantorre M, Laforce E, Eloot K, Delefortrie G (2007). Navigation in confined waters: influence of bank characteristics on ship-bank interaction. Proceedings of the 2nd International Conference on Marine Research and Transportation, Ischia, Naples, Italy, 1–9

[8] Norrbin NH (1974). Bank effects on a ship moving through a short dredged channel. Proceedings of the Tenth Symposium on Naval Hydrodynamics, Cambridge, 71–88.

[9] Söding H., Conrad F. Analysis of overtaking manoeuvres in a narrow waterway. Ship Technology Research, 2005, 52(4): 189-193

[10] Sutulo S, Guedes Soares C (2008). Simulation of the hydrodynamic interaction forces in close-proximity manoeuvring. Proceedings of the 27th Annual International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2008), Estoril. Portugal, OMAE2008-57938.

[11] Sutulo S, Guedes Soares C (2009). Simulation of close-proximity manoeuvres using an online 3d potential flow method. Proceedings of International Conference on Marine Simulation and Ship Manoeuvrability MARSIM 2009, Panama City, Panama, M-9-1-M-9-10.

[12] Sutulo S, Guedes Soares C, Otzen Janne F (2012). Validation of potential-flow estimation of interaction forces acting upon ship hulls in parallel motion. Journal of Ship Research (in press).

[13] Tuck EO, Newman JN (1974). Hydrodynamic interactions between ships. Proceedings of the 10th Symposium on Naval Hydrodynamics, Cambridge, Mass., USA, 35–69.

[14] Vantorre M, Delefortrie G, Eloot K, Laforce E (2003). Experimental investigation of ship-bank interaction forces. Proceedings International Conference on Marine Simulation and Ship Maneuverability (MARSIM’03), Kanazawa, Japan, 3, RC-31-1-RC-31-9.

[15] Vantorre M., Verzhbitskaya E., Laforce E. Model test based formulations of ship-ship interaction forces. Ship Technology Research/Schiffstechnik, 2002, 49: 124-141

[16] Zhou XQ, Sutulo S, Guedes Soares C (2010). Computation of ship-to-ship interaction forces by a 3d potential flow panel method in finite water depth. Proceedings of the 29th Annual International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2010), Shanghai, China, OMAE2010-20497.

[17] Zhou X.Q., Sutulo S., Guedes Soares C. Soares C. G., Garbatov Y., Sutulo S., Santos T. A. On computation of ship interaction forces in restricted waters using potential theory. Maritime Engineering and Technology, 2012, London, UK: Taylor & Francis Group